Virtual reality, cyberspace or presence--the technology that enables people to see, hear, feel, and walk around a computer generated world has captured the imagination of the public. For example, with tactile feedback devices at the fingertips, data gloves which present positioning information and a head mounted display may provide a realistic visual image which facilitates the interpretation of computer generated information. These images operate in accordance with predetermined modelling rules which can represent any physical system, real or imagined. Abstract systems imagined as physical systems, as well as real life physical systems, can be simulated. For example, the directories and files on a computer can be represented as interconnected objects. With this technology, the user can interact with the computer generated images in much the same way that he interacts with the real world.